Variable length drug delivery catheter

Abstract

A catheter for insertion in a physiological lumen is provided which includes two balloons, wherein the distance between the balloons can be adjusted. The catheter can be used for the delivery of a therapeutic substance for the treatment of conditions such as restenosis.

What is claimed is:  
     
       1. A medical device for insertion in a physiological lumen comprising: 
       a catheter assembly;  
       a first balloon element integrated with the catheter assembly;  
       a second balloon element integrated with the catheter assembly and capable of being nmoved towards and away from the first balloon element to create a treatment space when the first and second balloon elements are inflated; and  
       a first port in fluid communication with the treatment space to supply to or withdraw from the created treatment space a therapeutic substance.  
     
     
       2. The device of  claim 1 , wherein the catheter assembly is adapted to be inserted into the superficial femoral artery. 
     
     
       3. The device of  claim 1 , additionally including a second port in fluid communication with the treatment space, wherein the second port is used to supply to or withdraw from the created treatment space the therapeutic substance. 
     
     
       4. The device of  claim 1 , further comprising a third balloon element integrated with the catheter assembly, the third balloon element carrying a balloon expandable stent. 
     
     
       5. The device of  claim 1 , wherein the catheter assembly comprises: 
       a first catheter tube including the first balloon element; and  
       a second catheter tube disposed over the first catheter tube and including the second balloon element.  
     
     
       6. The device of  claim 1 , wherein the catheter assembly comprises: 
       a first catheter tube including the first balloon element, the first catheter tube having the first port disposed thereon; and  
       a second catheter tube disposed over the first catheter tube and including the second balloon element.  
     
     
       7. The device of  claim 1 , wherein the catheter assembly comprises: 
       a first catheter tube including the first balloon element, the first catheter tube having the first port disposed thereon; and  
       a second catheter tube including the second balloon element, the second catheter tube including a central lumen to receive the first catheter tube, wherein the inner diameter of the central lumen is sufficiently larger than the outer diameter of the first catheter tube so as to allow for the injection or withdrawal of a therapeutic substance from the gap between the surfaces.  
     
     
       8. A catheter assembly comprising: 
       a first catheter tube having a first lumen in fluid communication with a first balloon; and  
       a second catheter tube having a first lumen in fluid communication with a second balloon and a second lumen for slidably receiving the first catheter tube, wherein the outer diameter of the first catheter tube is smaller than the inner diameter of the second lumen so as to create a port through which a therapeutic substance can be applied to or withdrawn from a treatment zone created between the first and second balloons in an inflated state.  
     
     
       9. The catheter assembly of  claim 8 , wherein the first catheter tube additionally includes a port in fluid communication with a second lumen of the first catheter tube for applying to or withdrawing from the treatment zone the therapeutic substance. 
     
     
       10. A method for delivering a therapeutic substance to a physiological lumen comprising: 
       inserting a catheter assembly into a physiological lumen;  
       positioning a first balloon element disposed on the catheter assembly at a target area within the physiological lumen;  
       positioning a second balloon element relative to the first balloon element;  
       inflating the first and second balloon elements to create a treatment space; and  
       releasing a therapeutic substance through a first port of the catheter assembly in the treatment space.  
     
     
       11. The method of  claim 10 , wherein the act of-releasing comprises injecting a therapeutic substance added to a fluid carrier into a lumen of the catheter assembly which is in fluid communication with the first port. 
     
     
       12. The method of  claim 10 , further comprising removing the therapeutic substance through a second port. 
     
     
       13. The method of  claim 10 , wherein the catheter assembly is inserted into a superficial femoral artery. 
     
     
       14. The method of  claim 10 , further comprising adjusting the position of the second balloon element relative to the first balloon element by moving the second balloon element towards or away from the first balloon element. 
     
     
       15. The method of  claim 10 , wherein the catheter assembly comprises: 
       a first catheter tube supporting the first balloon element, the first catheter tube having the first port disposed thereon; and  
       a second catheter tube telescopically disposed over the first catheter tube and supporting the second balloon element.  
     
     
       16. The method of  claim 10 , wherein the catheter assembly comprises: 
       a first catheter tube supporting the first balloon element, the first catheter tube having the first port disposed thereon; and  
       a second catheter tube supporting the second balloon element, the second catheter tube including a central lumen for telescopically receiving the first catheter tube, wherein the inner diameter of the central lumen is sufficiently larger than the outer diameter of the first catheter tube so as to allow for the injection or withdrawal of therapeutic substances from the space between the surfaces.  
     
     
       17. The device of  claim 7 , wherein the cap between the surfaces is from about 0.25 mm to about 0.4 mm. 
     
     
       18. The device of  claim 8 , wherein the port created between the first catheter tube and the second catheter tube is from about 0.25 mm to about 0.4 mm. 
     
     
       19. The method of  claim 16 , wherein the space between the surfaces is fron about 0.25 mm to about 0.4 mm.